Dental casting machine



A.lume 9, 1925. i 1,541,180

J. E. PARKISON DENTAL CASTING MACHINE Filed Oct. 22, 1925 Patented June 9, 1925.

Unirse jsTATEfs 1,541,180 Flor-1.@

PATENT oF .JOHN E. PARKISON, OF SEATTLE, WASHINGTON.

DENTAL CASTING MACHINE. 'i

Application filed October 22, 1923. Serial No. 670,169.

f machines ofthe type .in which compressed air is employed for forcing the molten metal into the mold. y

rlhe object of the invention is to provide a machine of this kind in which the cap or cover for the mold ask may first be forced against the fiask with any desired amount of pressure so as to make a perfectly tight joint and the compressed air then admitted to the flask. More specifically, the invention aims to provide a construction in which a cap or cover for the flask is carried by a suitable support on which is pivotally mounted a suitable plate or handrest by which the cap may be pressed against the fiask and which may be tilted about its pivot point to admit compressed air to the'flask` A further object is to provide an arrangement in which the cap is adjustable relative to the support and-capable of being clamped in any desiredk position to accommodate flasks of diffeixnt heights. A still further object is to provide a machine which is simple and compact in construction and convenient in operation, requiring little space for its use, and one in which the parts are so arranged that the compressed air is compelled to travel only a short distance from the control valve to the casting flaskso that the air can be quickly applied to the molten metal inV the flask before the same cancool appreciably.

In the drawings :A Figure 1 is a plan view of my improved. machine,

Figure 2 is a longitudinal vertical section of the same substantially on the line 2--2 of Figure 1, Y

, Figure 8 is a longitudinal horizontal section of a part of the machine taken on the line 8-3of Figure 2,

Figure 4 is a transverse vertical-section on the linea-tofFigureQ. l. .ff

Referring to the drav'vings in'y detail, the numeral 10 represents the base or body of the machine. At 'one end of the base 10 I provide a 'compressed'air chamber 11 having a suitable air gauge 11*L and an opening 11b through ywhich air may be supplied. At

the .other endv of the base I provide a platform 12, upon which a flask A is adapted to rest, such flask containing the usual material B in which themold is formed, and also the ordinary depression C for containing the molten metal to be forced into the mold.

The platform 12 ispreferably provided with a series of lugs or projections 18 Which form centering .means for a plate such as la,

vwhich is loosely placed on the platform and which is provided with a central opening'for receiving the flask whereby it is accurately centered on the platform. A series of centeringplates such as 14 is preferably provided having different sized cntral openings to accommodate flasks of different diameter.

My improved machine is provided with a cap or cover 15 which is adapted to be forced down upon the flask placed upon the platform 12, the cap being preferably provided'with a disk 16 of moistened fiber or other suitablematerial. The cap 15 isfrigidly and preferably integrally conncted with j a valve casing 17, and these rparts are car- -ried by a suitable support by which the same may be moved toward and from a flask restiing on the platform.v Preferably such support comprises spaced arms or members 18 between which the casing 17 is arranged. These arms are preferably integrally connected at th ir front ends, and at their rear ends they are pivotally connected to the air chamber 11 by/means of a pivot rody 18 which extends through openings in the arms and in lugs 18b formed on said chamber. Between the inner surfaces of the arms 18 and the lugs 18h, I arrange friction Washers 18c of leather or other suitable material,

and a thumb nut 18d on the rod 18 can be adjusted to produce suflicient friction between said Washers and the adjacent parts to hold the arms 18 and the parts attached thereto in any positionto which they are moved. Each of said arms 18 near its rear end -is provided with a stop lug 18e which is adapted to contact with the'rear wall of the chamber 11 to limit the upward pivotal movement of the arms 18 and hold the rsame in raised position.

- The combined cap 15V and casing 17 is adjustably connected tothe arms 18 through the medium of lugs 2() integral With the cap and which are engaged by screws 21 extending througlhvthe armsjand into openingsin said lugs. One or both of said screws may be provided with wings2la by which the same may be tightened so that the combined casing and cap can b e clamped in rigid relation to the support formed by the arms 18.

The casing 17 is provided with an air passage 22 which communicates through the medium of a flexible pipe with the;coinpressed air chamber 11. This air passage communicates with a passage 22DL extending throughthe cap so' that compressed air may tlow` thro-ugh said passages and-:into a flask upon which the. cap is placed. The air passage 22 is controlled by a valve which is held to its seat by a coiled spring 25 arranged within the casing 17 and positioned between the valve and a screw plug 26 threaded into the rear end of the casing. A stem 27 secured to the valve 2d extends through a plug 2S threaded into the front Yend of the casino and forming a stuliinof box b 7, Zf

preventing' escape of around the stem. will be apparent that when the'valve 2st is opened compressed air may flow Vthrough the passages 22 and 22a and into a asl placed beneath the cap 15.

To provide means for manually pressing the cap 15 against a Crucible and for opening the valve 26, a member 30 is pivotally connected to the arms 18 of the supporhthis pivotal connection being effected by means of lugs 31 integral with the member 30 and ears 32 extending upwardly from the arms 18, a pivotipin 33 extending through aligned openings in said lugs and ears. The upper portion of the member 30 is shaped to provide a substantially 'flat hand rest 30 so shaped that the hand of the operator may be conveniently placed upon the same for forcing the parts downwardly toward the platferm l2. @n the under side of the member 30 there are rigidly secured downwardly projecting arms 84. the lower ends of which engage the rear ends of a bale 35, which bale extends forwardly and across the front end of the casing 1'?. This bale is adapted to contact with and move the stem 27 of the valve 24. To hold the bale in proper position to Contact with the stem there is provided a guide plate 36 having notched ends through which the bale passes, the intermediate portion of this plate being' provided with anopening` through which the stem 27 of the valve eX-tends.- It will be understood that when the member' 30 is moved about its pivotal connection with the arms 18, the arms 34 connected Vtherewith will draw the bale 35 rearwardly, thus forcing the stem of thevalve 27 into the casing and opening the valve. The spring 25 serves to close the valve 26 .an-d to restore the pa'rts to their original position when pressure on the member 30 is relieved. A

Briefly describing the operation ofthe devicayit vwill be understood.. that a .flask of the particular size which it is desired to use for making a casting is first placed on the platform 12. The cap 15 is then brought down firmly upon the upper edge ofthe Crucible', the' screws being loosened to permit the cap to takea position in which it willaccurately lit against the upper edge of the iiaslr.- @ne or both oiY the screws 21v is then tightened which rigidly loclrs the cap 15 and thecasingto the supporting member formed by the arms It will thus be apparent that in using crucibles of different size and height, which is necessary in dental work, the cap 15 can always be' adjusted and locked so that it will accurately lit the top of the Crucible' when it pressed down upon. the same preparatory to admitting the compressed air. After the: cap has thus been locked-in proper position and the Crucible with the molten metal therein is placed on the platform 12 and the cap brought down upon Jthe. crucible, the operator by pressing down upon the hand rest 30 may force the cap with any desired pressure into close engagement with the upper end of the Crucible so as to obviatezall danger of escape of compressed air. After the desired pressure ofthe cap aga'nst the Acrucible is obtained, by simply moving the hand so as to ti t the member 30 on its pivot, the arms 34 connected to this member will draw the bale 35 rearwardly against the stem A27 of the valve 26 and open the saine whereupon compressed air will flow through the passages 22 and 22a,r and into the crucible. (if course, the operations of pressing the cap against the flash and tilting the member 30 may be performed substantially simultaneously, that is, the downward pressure on Vthe member 30 may be so applied as to press the cap against the flask and at the same time automatically tilt this member to open the valve 2G: Preferably the spring 25 is made sufficiently strong so that when the support is forced downwardly by pressure on the member 30 in front of its pivot point, the' spring will offer sufliclent resistance to cause the cap to be forced tightly against the flaskbefore the member 30 tilts and opens the valve 26. After the casting operation is completed, and the hand ofthe operator is removed from the member 30, the

'spring 26 will again force the valve to its seat and through the medium of the stem 27, bale 35 and arms 34C, the parts will be returned to normal position. The friction washers 18c serve to hold the arms in any position rto which they are moved so that in using the machine it is not necessary toalways lift the arms to their limit whenv inserting or removing a liasl.V

.It will be noted. that by arranging the compressed air chamber betweenV the arms 18, it

it is possible to provide a very eopact and ,convenient arrangement, since all the parts are contained in little space and the vdevice can be used Where, little' room is available` Furthermore, by 'making the platformy and .Without departing from the spirit or principle of the invention. Y

Having thus described the inventionwhat is claimed as new and desired. to be secured by Letters Patent is:

1. In a casting machine, in combination, a cap adapted to rest on a casting flask and having' a passage for compressedair, a movable support for said'cap, a valve casing having a passage communicating With said first namedV passage, a valve in said-casing, a member carried by and movable with said support and forming :means for pressing ysaid cap agains'ta flask, said member also being movable relativevto said support, and means operated by the movementof said'member relative to said support-'for movingv said Ycarried by' and? movable lWith said support :and forming means for presslng sald--cap against a flask, said member also being movable relative to said support, 'and means operated by such relative movement of said member for moving said valve.

3. In a casting machine, incombination, a

casing having an air passage therein, a valve in said casing forcontrolling flow of air through said passage, a cap connected to said casing and adapted to rest on a flask, said cap having ana-ir passage communicating with said first named passage', a movable support for said cap, a hand' rest tiltingly mounted on said support and forming means for pressing said cap against a flask, and means operated by tilting movement of said hand rest relative to said support for moving said valve.

4. In a casting machine, in combination, a casing having an air passage therein, a valve in said air passage, a cap carried by said casing and adapted to rest on a flask, said cap having a passage communicating With said first named passage, a movable support for said casing and cap, a member mounted on and supported Wholly by said support and forming means for pressing said cap against a flask, said member being pivotally connected to said support and means operated by pivotal movement of said member relative to said supportfor moving Said valve. 5. In a casting machine, 1n combination, a base having achamb'er for compressed air,

Ya Vsupport pivotally connected to Asaid base,

commun'ating With said first named passage, a member tiltingly mounted on said support and forming means for, pressing said cap against a ask, yand means operated by the tilting of said member relative to said supp-ort for moving said valve.

6. In a casting machine, in combination, a valve casing, a movable support therefor, a cap connected to said casing and adapted .to be forced against a flask by movement of said support, said casing and cap having an ailpassage therein, a valve insaid :casing for controlling said passage, a member carried by said support and pivotally connected thereto, said lmember forming means by which Asaid cap may-,be forced .against 'a flask Without moving the member about its pivotal connection With said support, and

means operated by pivotal movement of said .member relative to said support for moving said valve.- g f v Y l7. In a casting machine, in combination,

a valve, casing, a cap carried thereby,` a movable support von Which said casingis mounted, said casing and cap having Van air passage therein, anvalvein said' casing for controlling. saidpassage, a lever-,pivotallyconnectedto said casing, oney portion of said lever being shaped to provide a hand rest by Which said cap may be forced` against a flask Without movement of the vlever about its pivot, and means operated bypivotal movement of said `lever relative to thev support for moving said valve. i

8. In a casting machine, in combination a valve casing, a c ap carried thereby, a movable support on which said casing is mounted, said casing and cap having an air passage therein, a valve in said casing for controlling said passage, said valve having a stem extending outside of said casing, a member pivotally connected to said support and forming means for manually forcing said cap against a Crucible, and means operated by pivotal movement of said member relative to the support for moving said valve stem to operate said valve.

9. In a castingmachine, in combination,

a valve casing, a can carried thereby. a mov- Cil tion arranged above said casing and a hand rest by which said cap may be manually forced against a crucible without movement of said member relative to said support, said member also having an arm below said first named portion, and means operated by said Varm for opening said valve when said member is moved relative to said support.

10. In a casting` machine in combination, a valve casing, a cap carried thereby, a movable support fon which said casing is mounted, said casing and cap having air passage therein, a valve in said casing for controlling said passage, a member pivotally connected to said support and having a substantially fiat portion arranged above said casing and forming a hand rest by which said cap may be forced against a cruoible, said member also having arms extending downwardly from said flat portion on opposite sides of said casing, and` means operated by said arms for openings-aid valve when said member is moved. about its pivotal connection with said support. Y

1l. In a casting machine, in combination, a cap adapted to contact with a casting flask and having a passage for compressed air, a movable support for said cap, said cap being ladjustable relative to said support, means 'for Clamping'saidl cap to the support in any desired position of adjustment, a valve casing rigid with said cap having AVa passage communicating with said first named passage, a valve in said casing, and means oarrie'd by said support for operating said valve. Y

12. In a casting machine, in combination, abase, a valve casing, a support for the same pivotally connected to said base, a cap rigid with said casing', said casing and cap being adjustable"relative to said support, means for clamping said capI and casing to said support in any desired position of adjustment, a valve m said casing, and means carried by said support for opening said valve to" permit compressed air to `fiovv through said casing and cap.

1S. In a casting machine, lin combination,

to, a valvel casingV carried by said support,

Va valve in said casing, a cap rigidly secured to said casing,'said cap` and casing. being adjustably connected to said support, means for clamping said cap and casing to the support in any desired position of adjustment, a member carried by said support and forming means for pressing said cap against a flask, said member being pivotally connected to the support, and means operated 4by pivotal movement of said 'member relative to the support for moving said valve.

lt. In a casting machine, in combination, a base having at one end a platform for holding a flask and at the other endy achamber for compressed air, arms pivotal'ly connected to the-last named end of the base, a cap carried by said arms and adapted to be brought intov contact with a flask on said platform, a valve casing connected to said cap, avalvel in said casing, said ycap and casing having a passage for compressed. air, a flexible conduitfor conducting compressed air from said chamber to said passage, a member carried by said arms and forming means for pressing said cap against a ask, said member being pivotally connected to said arms, and meansV operated by movement'of said member relative to said arms for moving said valve. y i

15. In a casting machine, in combination, a base, arms pivotally connected thereto, a

-cap carried by Said arms, a valve casing connected to said cap, a valve 1n -s'ard casing, a

member pivotally connected to" said arms and forming means for 'pressing said cap against a flask, means operated byI pivotal movement of said member relative to said arms ,formov'ing said valve, andy friction means arranged at the pivotal connection between said base and arms for holding the latter in any' position to which they are moved.

In testimony whereof I hereunto afiiX' my signature.

JOHN nPAnKrsoN. 

